The wind has historically been one of the most widely used natural resources to provide the energy necessary to power our needs. As the demand for energy has increased and the supplies of fossil dwindled, the result has been a renewed look by electrical utility companies at alternative methods for producing electrical power. One method of electrical production involves the harnessing of wind by a turbine to drive an electrical generator.
Wind turbines typically involve using a series of blades fixed to the top of a tower to rotate about a horizontal axis. The blades have an aerodynamic shape such that when a wind blows across the surface of a blade, a lift force is generated causing the series of blades to rotate a shaft about an axis. The shaft is connected, typically via a gearing arrangement, to an electrical generator located in a structure called a nacelle which is positioned behind the blades. The gear box converts the rotation of the blades into a speed usable by the generator to produce electricity at a frequency that is proper for the electrical grid it is providing power.
The nacelle houses a number of components which are needed for operation of a modern high capacity wind turbine. In addition to the aforementioned gear box and generator, other components include a yaw drive which rotates the wind turbine, various controllers, and a brake that is used to slow the generator. Since it is desirable to keep the nacelle as small as possible, and given the number of relatively large pieces of equipment which must be located in the nacelle, space becomes very valuable. This often results in difficulties in both manufacturing the wind turbine and in conducting maintenance operations in the nacelle once the wind turbine is installed.
Accordingly, it is considered desirable to provide a wind turbine which minimizes the size of the nacelle while providing adequate accessibility to components during maintenance operations.